I read once, online, someone (perhaps in the Tibetan tradition if that matters) saying that the four brahmaviharas are inter-related -- in particular, that too much of one is counteracted by a bit of another.

For example:

* Feeling too sorry for someone (too much compassion/karuna) is counteracted by a bit of mudita (remembering the ways in which that person is virtuous or fortunate)

* Similarly, too much of each of the other three is counter-balanced by a bit of each of the othersI was reminded of it by this answer ("in good there is seed of bad").

I don't remember the explanation I read, though, and I wasn't able to find the reference again.

Is that anything you've heard before? If you know the explanation but don't know a reference for it, that's OK too (I'd be happy to read just your explanation of it even without a reference).

...As part of right concentration, all four brahmavihāras can function as objects of jhāna, the strong levels of concentration that strengthen the mind’sability to make the sublime attitudes truly unlimited. The concentration based on these attitudes can also provide the mind with the steadiness and inner strength it needs for discernment to break through to total release.

Because the brahmavihāras function both toward the beginning and again toward the end of the path, they have an interactive relationship with all the other path factors. On the one hand, they provide the motivation to practice right speech, right action, right livelihood, right effort, and right mindfulness both for one’s own good and for the good of others. On the other hand, the development of concentration based on the brahmavihāras requires, as a prerequisite, that you work on making your thoughts, words, and deeds harmless, for otherwise your concentration will be undermined by hypocrisy. Actually, all the factors of the path have an interactive relationship, interpenetrating and strengthening one another along the way. This means that the brahmavihāras, as elements in right resolve and right concentration, also strengthen right view, the first factor of the path, just as right view gives them guidance.

To begin with, right view is not simply a collection of facts about the world. Instead, it focuses attention on a single problem, which is an issue of goodwill and compassion: how to understand causality in a way that helps put an end to suffering. In this way, the brahmavihāras provide direction for the use of discernment on the path.

At the same time, the brahmavihāras in the context of the path take their guidance from right view so that they don’t flounder around in wishful thinking or ineffectual resolves. Instead, grounded in a clear understanding of cause and effect, they are focused on the most effective ways of achieving their aspirations.